The proposed research concerns the ability of people to make intuitive statistical estimates which are considered to reflect the processes underlying cognitive probability estimation. The experimental paradigm involves the rapid (e.g., 0.5 sec/stimulus) presentation of numverical stimuli and subsequent estimation of characteristics of the stimuli. Two conceptual approaches are described. One involves intuitive averaging of numerical stimuli. Previous research suggests that estimates of the average of a distribution of numerical stimuli are affected by interference. A line of research is proposed to investigate this. Previous research also suggests that the memorial representation of the numerical stimuli was analog. A line of research is proposed to investigate this. The second conceptual approach is to study intuitive estimation of the correlation between two distributions of stimuli. Subjects will be presented many pairs of numbers and later be asked to estimate one given another. Test stimuli will not have been shown previously. Two lines of research are proposed to investigate this paradigm. The goal of the research is to study the cognitive processes underlying intuitive statistical estamation and probality estimation.